<template>
  <el-breadcrumb class="app-breadcrumb" separator="/">
    <transition-group appear name="breadcrumb">
      <el-breadcrumb-item v-for="(item, index) in levelList" :key="item.path">
        <span v-if="item.redirect === 'noRedirect' || index == levelList.length - 1" class="no-redirect">{{ item.meta.title }}</span>
        <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
      </el-breadcrumb-item>
    </transition-group>
  </el-breadcrumb>
</template>

<script>
import { pathToRegexp } from "path-to-regexp";
import { ref, defineComponent, watch } from "vue";
import { useRoute, useRouter } from "vue-router";

export default defineComponent({
  name: "BreadCrumb",
  setup() {
    const levelList = ref([]);
    const route = useRoute();
    const router = useRouter();

    const isDashboard = (route) => {
      const name = route && route.name;
      if (!name) {
        return false;
      }
      return name.trim().toLocaleLowerCase() === "Dashboard".toLocaleLowerCase();
    };

    const getBreadcrumb = () => {
      let matched = route.matched.filter(item => item.meta && item.meta.title);
      const first = matched[0];
      if (!isDashboard(first)) {
        matched = [ { path: "/", meta: { title: "首页" } } ].concat(matched);
      }
      levelList.value = matched.filter(
        item => item.meta && item.meta.title && item.meta.breadcrumb !== false
      );
    };
  
    const pathCompile = (path) => {
      // To solve this problem https://github.com/PanJiaChen/vue-element-admin/issues/561
      const { params } = route
      const toPath = pathToRegexp.compile(path)
      return toPath(params)
    }

    const handleLink = (item) => {
      const { redirect, path } = item;
      if (redirect) {
        router.push(redirect.toString());
        return;
      }
      router.push( pathCompile( path ) );
    };

    getBreadcrumb();

    watch(
      () => route.path,
      ( route ) => {
        // if (route.path.startsWith('/redirect/')) {
        //   return
        // }
        getBreadcrumb()
      }
    );

    return {
      getBreadcrumb,
      pathCompile,
      handleLink,
      levelList,
    };
  }
});
</script>

<style lang="scss" scoped >
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  font-size: 14px;
  line-height: 50px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>
